Coolant Bypass

[Ram360man]

Engine came out of a bus. Instead of a freeze plug in the back of the engine it has the factory plate with a nipple to put a hose on. Only question I have is where to plumb the hose back into? was thinking about plumbing it into the upper radiator hose but not sure if this is the best idea.

[BC847]

That originally fed coolant to the air compressor that was mounted where our PS/Vacuum pump is. The return for it should be about the middle/driver's side of the head.

You might consider running a line from there back to one of the inlet fittings under the alternator. It would circulate just that much more coolant through the cylinder portion of the block.

Else, just plug it.

[Ram360man]

I used the head off my truck so the plug is still in it. Looks like a pain to get at that one. Wouldn't running it to the upper radiator hose help it run cooler though instead of pumping hot coolant through it again? Im going to plug it for now anyways. Just like to get it functional someday after I get it running again. haha.

[BC847]

Wouldn't running it to the upper radiator hose help it run cooler though instead of pumping hot coolant through it again?

The idea is it promotes more uniform cylinder temps while still providing full flow through the head.

At least that's what I understand.

[Tacoclaw]

You'd have to run it in before the thermostat, wouldn't you? If you just run it into the top of the housing you'd have a 5/8" bypass around your thermostat, I think, wouldn't that make it take forever to warm up?

[Ram360man]

I was going to run a shut off valve and only open it up for towing or sled pulling. Guess I will t it in with the heater lines if it's going to restrict flow to the head.

[12vsuburban]

I'll be doing this to my trucks. For our trucks it has a major benefit of more equal cooling which helps the rear cylinders not get so hot and hurt themselves. As a bonus with more equal temps along the entire block will equal more even air/fuel mixture which will increase performace even if minimal...but its free power! This is a common modification to do on Chevy V8s as well , we do it on our race motors as even with only 4 cylinders in a row there is always hot and colder areas which equals uneven afr's. You can see a HP improvement on the dyno on typical gas motors, I dont see why we wouldn't see it in our oil burners as well....
Hans

[rockmike]

Could I get some more details on this bypass guys? Im replacing my head this week.Now would be the time to put a pipe nipple on that back freeze plug and run it to the "inlet under the alt position"? is there a plug in a water gally under there that i pull and install a pipe nipple into that? this "bypass" will help keep head coolant temps more uniform?

How do I do this exactly?

Thanks,appreciate y'alls time and knowledge.

[dazedandconfused]

http://www.puredieselpower.com/catalog/ ... -1374.html

[Tacoclaw]

I suppose you could technically run it to any forward point on the block. The point of this thing isn't really to even out heat, though it may work like that, it's real point it to bleed off pressure in the back of the head when the engine is revving really high. Apparently the water pump is capale of putting out more water than the system can handle at high RPMs and it causes excess pressure at the rear of the block, farthest away from any drains.

If you don't rev your truck up really high or get it really hot towing the bypass could be a waste of time/$$. The "billet" freeze plug is a good PM measure though, just in case.